The portable telephones, particularly smartphones, are now widely used and various applications have appeared. Of these, applications using speech input are believed to become popular, partly because it is difficult to input texts on a small device such as a smartphone.
Among such applications using speech input, for those types of applications which requires uttering a series of simple texts such as “YES/NO” displayed on a screen, the user never wonders to say next. If speech input is used as a tool for communication with another person such as in the case of speech translation, however, it is common that the user hesitates to use such an application, as the user is not sure what to input by speech. Assume a trial of speech translation application. Often, the user will be at a loss as to what to say to start.
Further, it is not uncommon that the user hems and haws “uh” or “er” before actually starts an utterance. Such meaningless sound decreases accuracy of speech recognition.
A situation in which one must say something but cannot think of what to say is common and such a problem is not limited to the field of speech translation. Such a situation occurs when we talk to other people. Sometimes we run out of conversation topics and just cannot find anything to say next.
Patent Literature 1 specified below discloses a topic suggesting device for presenting topics to keep conversation going when they run out of topics. According to the disclosure of Patent Literature 1, the system uses topics database storing topics and keywords associated with the topics, with the keywords selected from viewpoints commonly used for topics. There are different viewpoints prepared in advance. This system operates as follows: words and phrases are extracted from conversations of users; weight of each of the words and phrases with respect to each of the viewpoints is calculated; the topic last presented to the user is compared with each of the topics stored in the topics database and similarity therebetween is calculated viewpoint by viewpoint; the similarity is multiplied by the weight of word/phrase calculated for each viewpoint, and the sum of multiplication results is obtained. The topic having the largest sum is presented to the user as a suggestion of the new topic. The viewpoints typically include the so-called “5W1H.”
According to Patent Literature 1, the device can present a topic that is close to the viewpoint at the center of current conversation and far from other viewpoints.